Mold for casting shells.



J. C. McLACHLAN. MOLD FOR CASTING SHELLS. APPLICATION FILED OCT. I8, 1915. RENEWED 05c. 22. 1916,

Patented Feb. 13, 1917.

20 quicker J'OHH C. MoLACHLAN, TORONTO, ONTARIO, CANADA.

MOLD FOB, CASTING SHELLS.

Application filed October 18, 1915,"Seria1 No. 56,365. Renewed 11 member 22, 1916.

To all whom it may concern.

Be it known that I, JOHN CAMPBELL MC- LAcHmN, a subject of the King 'of Great Britaim'and resident of the city of Toronto,

6 count} of York, Province of Ontario, in the Dominion of Canada, have invented certain new and useful Improvements in Molds for- Casting Shells, as described in the following specification and illustrated in the ac. 10 companying drawings, that form part of the same.

The objects of the invention are, to effect a material reduction in the cost of manufacturing shrapnel, or other explosive shells, 1 and to produce by a casting process a shell having all the requirements "of hardness, smoothness of surface and accuracy of weight and balance. g

A- further object is to obtain greater and I production of explosive war munitions.

The principal feature of the invention .consists in the novel construction of a mold and the method of casting the shell,

= whereby the shell is completed and requires practically no machining after its removal from the mold. i

In the drawings, Figure 1 represents a vertical elevational view of a mold used in constructing shells in accordance with this invention, one-half being in longitudinal section.

-Fig. 2 is a partial top plan view.

Fig. 3 is a partial section taken horizontally through the line -6 of Fig. 1.

Like numerals of reference indlcate corresponding parts in each figure.

In carrying this invention into effect it is intended to cast the body of the shell in a chill mold, thus producing a smooth, accurate and uniform surface for contact with the inner bore of the gun from which it is to be fired. The mold consists of a circular-shaped base 1 having a central circular boss 2 formed thereon and provided with a centrally arranged cylindrical opening 3.

4 are the chill sections comprising a pair of half round members each formed with z flange 5 to rest upon the base 1 and a mess 6 to receive the boss 2. The outer valls of the chills are formed with a pluality of circumferentially arranged ribs 7 vhich disperse the heat quickly and effect rapid cooling of the cast member. The pper ends of the chill sections are formed Specification of Letters Pate: t.

. within the Patented Feb. 13, 1917.

Serial No. 138,492.

with an enlarged annular recess 8 adapted to receive zhe head block 9 which'is secured in posltloi by means of the fastening ring 10 which is held by suitable clamps not shown.

.The heal 9 is and 12 forming the pouring entrance and gas vents respectively:

13 is an annular recess formed in the inner wall of the chills adjacent to the upper end and in which is placed a dry sand core 14: adapter to form a dovetailed shaped groove in lhe external surface of the shell.

hlS groo e is vented by means of the holes 13.

15 is a tubular perforated core center extending through the cylindrical opening 3 and rigidly supported in central alinement mold formed by the chills 4.. This tube :s shown with a rounded upper end 16 periorated aiidan open bottom end 17. Around the core center 15 is formed a dry sand (ore 18 which is shaped externally to the exact inner shape of the shell to be cast.

19 is a sleeve fitted into the opening 3 in the base aid surrounding the core center 15 and forming a rigid support for same, the upper (11d thereof abutting a ring 21 on the core center.

The sleev and core center are locked in position by a key 22 or other suitable fastening engaging the lower end of the core center which extends through the base.

The end cf thesleeve 19 extending above the base is threaded externally to form a chill surface for the threaded central opening of the S1811 and the sleeve is separable from the ba: 1e so that it can be readilyunscrewed from the shell when cast, the thread being coated with a thin coat of tar and plumbago.

The semi -cylindrical chill members 4 which are provided with radial edge flanges adapted to it snugly together and held in register by suitable dowel pins are fastened togetk er by any suitable form of clamps whicl. are not here shown.

In carrying out the manufacture of shells according to ;his invention the molds are set up in the ma: mer shown and as the metal is poured, the exterior of the shell is at once chilled by contact with the outer metal case. The interior vall of the mold is coated with a thin coating of tar and plumbago which prevents the metal sticking to the sides of provided with openings 11 i the-mold and also insures its free and uniform flow to form a very closely grained and dense surface free from defects. The central dry sand core allows the escape of gases generated within the mold to the perforated core center 15 and these are rapidly dissi- 'pated without creating internal pressures and thus allow the metal as poured to form I into a uniformly dense mass throughout the to cool very quickly and be ready for furother than to clean out the threadand apply the copper j'gas ring to the dove-tailed recess. The cost of manufacture is thus reduced to. the minimum and rapidity of pro l having a central openin a sectional chill forming the outer wallo 'duction is assured;

' What I claim as my inventionis'z- 1. A shell mold, comprising, a rigid base he mold adapted to be centered upon and removably securedto said base, a hollow perforate core center centered in the opening in said base and provided with a projecting shoulder forming a support for the core, means engaging the lower end of said core center and adapt- .ed to clamp same rigidly to said base to rigidly support same axially within the mold, and a head block closing the top of the mold and havingpouring and overflow vents.

., 2 A shell mold comprising, a base having a central opening, a sectional chill adapted to be centered upon and removably secured to said base to form a,mold, a sleeve cen tered in the opening in said base and extending upwardly therefrom and having a threaded exterior forming the inner wall of the lower part of the mold, and a perforate core center rigidly supported in said sleeve and extending upward y into the mold;

3. A shell-mold, comprising, a base having a central 'opening,'.a sleeve fitted in said opening andextending perpendicularly upward from said base, said sleeve having a threaded exterior, a perforate tube extending through said sleeve and having a ring resting upon the upper end of said sleeve,

- means connected to the bottom of said perforate tube for locking'said tube and sleeve insaid base, a sand core encircling said perforate tube and a sectional chill centered upon said base and surrounding said core and having pouring and vent openings at the top.

Signed at the city of Toronto, county of- York,-Province of Ontario, in the Domin: ion of Canada, this 13th day of- October J. G. MOLACHLAN. Witnesses;

E. HnnoN, I A. G. KELLY. 

